1. Field of the Invention
The present invention relates to a control apparatus for a gas turbine engine.
2. Description of the Prior Art
Gas turbine engines used for automobiles usually comprise a single rotating shaft assembly or double rotating shaft assemblies. Most gas turbine engines with a single rotating shaft assembly have variable inlet guide vanes (VIGV's) installed in the inlet portion of the compressor for adjusting the flow rate of the intake air. On the other hand, most gas turbine engines with double rotating shaft assemblies have both VIGV's installed in the inlet portion of the compressor and variable nozzles (VN's) installed in the inlet portion of the power turbine to adjust the flow rate of gas. During an accelerating condition of the engine, VIGV's are operated toward the opening direction to increase the flow rate of the intake air. The amount of fuel is also increased to raise the gas temperature in the inlet portion of the power turbine, thereby increasing the engine acceleration performance. The VN's are also operated toward the opening direction to raise the gas temperature at the inlet port of the gasifier turbine in order to increase engine acceleration performance.
In the conventional art, operation speeds of the VN's and VIGV's are maintained constant at all times. This, however, is a problem. Generally, VN's and VIGV's are operated at speeds as great as possible (maximum speeds) to improve engine acceleration performance at full throttle. With the VN's and VIGV's being operated at maximum speeds at all times, however, the VN's or VIGV's may operate at fast speeds even under an acceleration condition in which the running speed of the compressor should be increased by a small amount, causing the running speed of the compressor to be greatly changed. Therefore, when an automobile mounting a gas turbine engine of this type is run according to a predetermined running pattern, fuel is consumed in very large amounts, deteriorating the fuel efficiency.